Method for Doffing for a Spinning Machine and a Corresponding Doffer

ABSTRACT

A method for removing full bobbins from spindles of a ring spinning machine and for setting down empty sleeves on the spindles using a doffer is disclosed. The doffer has a beam and a rotatable gripping device that is mounted on the beam and has a sleeve gripper and a bobbin gripper, wherein the doffer is arranged next to the ring spinning machine. The beam is raised vertically and the gripping device is extended from the beam over the full bobbin. The invention also relates to a doffer having the corresponding drives.

FIELD OF THE INVENTION

The present invention relates to a method for removing full bobbins fromspindles on a spinning machine and setting down empty sleeves on thespindles using a doffer. The invention also relates to a doffer for aring spinning machine having a plurality of spinning stations.

BACKGROUND

Doffer apparatuses for spinning machines are well-known. The dofferapparatus usually has a plurality of gripping devices so that a grippingdevice is assigned to each spinning station. In many cases, such agripping device has a gripper, which first removes a full bobbin from aspindle and sets it down on a journal on a conveyor belt, for example.Then the gripper grips an empty sleeve for example from a journal on aconveyor belt, and places it on the spindle. Between the removal of thebobbin and the placement of the sleeve, a beam on the doffer apparatuson which the gripping devices are arranged must be moved from thespinning station to the conveyor belt and back again to the spinningstation. Because of the size of the doffer apparatus, this movement isusually time consuming, which causes spinning time to be lost.

To solve this problem, Swiss Patent CH 676724 describes a dofferapparatus having gripping devices, each of which is provided with twocontrollable gripping elements for gripping sleeves and bobbins. Thegripping elements there are accommodated in a rotating disk driven by anadjusting drive. For a doffing operation, the first gripping elementfirst grips an empty sleeve. Then the beam on the doffer apparatus movesthe gripping devices together with the empty sleeves toward the spinningstations. At the spinning station, the second gripping element thenremoves the full bobbin from the spindle. Next, the adjusting driverotates the rotating disk, so that the first gripping element is setdown with the empty sleeve over the spindle. Then the first grippingelement sets down the empty sleeve on the spindle. Once this is done,the spinning process can be continued. With this doffer apparatus, wideareas of the beam are avoided during the downtime of the spinningstations, which thus saves time. But one disadvantage of this dofferapparatus is that, in the direction of the longitudinal axis of thespinning machine, the gripping devices with the rotating disks requiremore space than what is available between two spinning stations on manymodern spinning machines. Furthermore, the demand for space is increasedin an unfortunate manner with this embodiment because the doffer tiltsout at the side.

French Patent FR 589966 discloses a doffer double gripper, which picksup the completed bobbins/cops and sets the empty sleeves down. However,one disadvantage of this embodiment is the lower fastening of thesleeves/cops because this is a stability problem.

SUMMARY OF THE INVENTION

An object of the present invention is thus to create a method and arespective doffer apparatus which will allow a rapid doffing operationwith restricted available space. Additional objects and advantages ofthe invention will be set forth in part in the following description, ormay be obvious from the description, or may be learned through practiceof the invention.

The present objects are achieved by the features described and claimedherein.

The objects are achieved in particular by a method for removing fullbobbins from spindles on a ring spinning machine and setting the emptysleeves down on the spindles using a doffer, wherein the doffer has abeam and a rotatable gripping device mounted on the beam with a sleevegripper and a bobbin gripper. The doffer is arranged next to the ringspinning machine. The method comprises the following method steps:

(a) Gripping an empty sleeve with a sleeve gripper;(b) Vertical raising of the beam;(c) Extension of the gripping device from the beam over the full bobbin;(d) Removing the full bobbin from the spindle with the bobbin gripper,rotating the gripping device and setting the empty sleeve down on thespindle;(e) Retracting the gripping device toward the beam;(f) Vertical lowering of the beam, and(g) Placement of the full bobbin.

In particular, advantages are provided by a doffer having a beam and arotatable gripping device mounted on the beam, and having a sleevegripper and a bobbin gripper, wherein the doffer can also be arrangednext to the ring spinning machine. The ring spinning machine comprisesspindles, comprising a drive for vertically raising and lowering thebeam, and a drive for extending and retracting the gripping device fromthe beam over the spindles.

The method according to the invention and the doffer according to theinvention are advantageous because they are very space saving, and themachine is not made wider due to the lateral extension of the doffer.Furthermore, this is a very simple design.

In a first specific embodiment, the gripping device is pivoted outwardfrom the beam in the horizontal direction. A simple joint isadvantageously used here between the beam and the gripping device. Inthis case, after gripping the empty sleeve, the gripping device executesa rotational operation to thereby bring the bobbin gripper into thecorrect position for removing the filled bobbin.

In a second specific embodiment, the gripping device is pivoted outwardfrom the beam in a pivoting movement of the gripping device, which isdirected from below to obliquely upward. The gripping device here willexecute a vertical offset to arrive at the working position for removingthe full bobbin.

Depending on the space requirements, the rotational operation of thegripping device can be carried out before placement of the empty sleeveson the spindles, retraction of the gripping device toward the beam,wherein the gripping device is extended again over the spindles afterthe rotational operation. Alternatively, the rotational operation of thegripping device may also take place directly over the spindles withoutrequiring any retraction and extension of the gripping device.

The bobbin gripper advantageously has a bobbin receptacle that is opentoward the bobbin, and the sleeve gripper has a sleeve receptacle thatis open toward the bottom and can be inverted over the bobbin and/or thesleeve for gripping it from above. The sleeve gripper and the bobbingripper may be designed to be cylindrical or conical. The conicalembodiment has the advantage that it provides a better hold of thesleeve and the bobbin, in particular when the two are pneumaticallyoperated because the membrane is better adapted to the sleeve and thebobbin.

In an advantageous refinement of the invention, each gripping unit hastwo indicators by which the position of the rotational device is visiblethrough a basic body. If a malfunction has occurred and the operatormust reengage or equip a gripper unit, he can recognize the correctposition from the outside. The two indicators must be set in alternationin the case of neighboring gripping units, so that the gripping unitscan be positioned and the missing gripping unit can be used correctly.

Finally, it is advantageous if the angle between the axis of rotationand the bobbin gripper axis is equal to the angle between the axis ofrotation and the axis of the sleeve gripper. It is thus possible toachieve the result that, after rotation of the gripping unit, thepositions of the bobbin gripper and the sleeve gripper are exactlyswitched, which then facilitates rapid placement of the empty sleeve.

In an advantageous specific embodiment, an axis of the bobbin gripperand an axis of the sleeve gripper may be arranged at an angle to oneanother, which is between 4° and 20°, especially preferably 15°. Theangle between the axis of rotation of the gripping device and the axisof the bobbin gripper may also be equal to the angle between the axis ofrotation and the axis of the sleeve gripper.

BRIEF DESCRIPTION OF THE FIGURES

Additional advantages of the invention are described in the followingexemplary embodiments in which:

FIGS. 1a-j show schematic diagrams of a first specific embodiment ofviews of certain phases in changing from full bobbins to empty sleevesin the method according to the invention; and

FIGS. 2a-g show schematic diagrams of another specific embodiment ofviews of certain phases in changing from full bobbins to empty sleevesin the method according to the invention.

Only the features that are important for the invention are shown. Thesame features are provided with the same reference numerals in differentfigures. The directions of movement are indicated with arrows.

DETAILED DESCRIPTION

Reference will now be made to embodiments of the invention, one or moreexamples of which are shown in the drawings. Each embodiment is providedby way of explanation of the invention, and not as a limitation of theinvention. For example features illustrated or described as part of oneembodiment can be combined with another embodiment to yield stillanother embodiment. It is intended that the present invention includethese and other modifications and variations to the embodimentsdescribed herein.

FIG. 1 shows schematic diagrams of a first specific embodiment of viewsof certain phases in changing from full bobbins 7 to empty sleeves 5 onspindles 8 of a ring spinning machine according to the present method.The starting position for a changing operation according to theinvention from bobbins 7 using the doffer apparatus 1 is illustratedschematically in FIG. 1a . The doffer apparatus 1 comprises a dofferbeam 2 and a plurality of rotatable gripping devices 3 using twogripping elements 4 ₁, 4 ₂, so that a gripping device 3 is assigned toeach spinning station on the ring spinning machine. The figuresillustrate a gripping device 3 merely as an example, but severalgripping devices 3 are arranged along the ring spinning machine. Themultiple gripping devices 3 are mounted on the beam 2. Furthermore, thebeam 2 can be moved in such a way that it can bring the gripping devices3 into the positions relevant for the doffing operation in order toreceive the empty sleeves 5 from the pin 6 of a conveyance system anddeposit the full bobbins 7, and toward the spindles 8, in order toremove the full bobbins 7 and set down the empty sleeves. To do so, thegripping device 3 comprises as the first gripping element a sleevegripper 4 ₁ and, as the second gripping element, a bobbin gripper 4 ₂.The bobbin gripper 4 ₂ is designed for gripping the full bobbin, and thesleeve gripper 4 ₁ is designed for gripping the empty sleeve. It isprovided that the two gripping elements 4 ₁, 4 ₂ of the gripping device3 can be rotated so that they mutually change positions.

The sleeve gripper 4 ₁ and the bobbin gripper 4 ₂ each have a sleevereceptacle that is open at the bottom and can be inverted over thebobbin 7 and/or the sleeve 5 for the purpose of gripping them. The twoelements may be designed to be cylindrical or conical and may beoperated pneumatically with a membrane. The diameter of the sleevegripper 4 ₁ and the diameter of the bobbin gripper 4 ₂ areadvantageously the same, in particular when the sleeve gripper 4 ₁ andthe bobbin gripper 4 ₂ are designed to be essentially identical. In anadvantageous specific embodiment, one axis of the bobbin gripper 4 ₂ andone axis of sleeve gripper 4 ₁ can be arranged at an angle to oneanother, which is between 4° and 20°, especially preferably 15°. Theangle between the axis of rotation of the gripping device 3 and the axisof rotation of the bobbin gripper may also be equal to the angle betweenthe axis of rotation and an axis of the sleeve gripper.

It is also the case that two neighboring gripping devices 3 can berotated with a time lag between them. This is a particularlyspace-saving embodiment. Each gripping device 3 may then have twoindicators, where the position of the rotational device is indicatedthrough a base body.

In a first variant of the method according to the invention, the gripperbeam 2 is first positioned so as to grip each of the empty sleeves 5with a sleeve gripper 4 ₁ of the gripping devices 3 and to lift them upfrom a pin 6. As can be seen in FIG. 1b , the beam 2 is raisedvertically according to the invention by a drive, which is not shown ingreater detail here. FIG. 1c shows that the gripping device is thenrotated about an axis of rotation in order to be able to receive thefull bobbin 7 in a working position with the unoccupied bobbin gripper 4₂.

With the ring spinning machine shut down, the full bobbins 7 are grippedat their sleeves by the gripping elements of the gripping devices 3. Theempty sleeves 5 are situated on the side of the spindles 8 facing awayfrom the machine frame during this operation. In this method step, thegripping device 3 is extended and/or unfolded horizontally from the beam2 (see arrow), in order to be positioned over the bobbins 7, and then islowered (FIG. 1d ). The horizontal pivoting and/or unfolding of thegripping device 3 takes place by way of articulated connections that arepresent between the beam 2 and the gripping device 3.

Next, the bobbin 7 is gripped and the gripper beam 2 is moved verticallyupward in order to remove the bobbins 7 from the spindles 8. If thebobbins 7 are free of the spindles 8, then the gripping device 3 isrotated again by 180°, so that the empty sleeves 5 enter the positionflush with the spindles 8. In this process step of rotation, the grippercan be moved and/or rotated into the position in FIG. 1b and shiftedback to the spindle 8 (FIG. 1e ). Alternatively, the gripper 3 canrotate over the spindles 8 (not shown in the figures). The empty sleeves5 are again placed on the spindles 8 due to a vertical downward movementof the doffing beam 2. The end of this changing phase is illustrated inFIG. 1f . As shown in FIG. 1g , the doffer beam 2 is again retractedwith the full bobbins 7 (cf. arrow). At the latest at this point intime, the ring spinning machine that has been stopped can be started upagain.

FIGS. 1h-j show the lowering of the doffer beam 2 and the simultaneousrotation, so that the bobbins 7 are moved out of their waiting positioninto their subsequent position that is flush with the pin 6. In FIGS.1i,j the gripper elements 4 ₂ holding the full bobbins 7 are in theposition in which they are flush with the pin 6. By lowering the dofferbeam 2 vertically and then releasing the gripping elements 4 ₂, thebobbins 7 are dispensed to the pins 6. Then the doffer 1 goes back to aresting position. The operation of changing full bobbins 7 for emptysleeves 5 is thus concluded.

FIG. 2 shows schematic diagrams of a second specific embodiment of viewsof certain phases in changing full bobbins 7 for empty sleeves 5 on aring spinning machine in the method according to the invention. In FIG.2a , the starting position is diagramed schematically for an operationof changing bobbins 7 with the doffer apparatus 1 according to theinvention. The doffer apparatus 1 per se corresponds to the exemplaryembodiment of FIG. 1, as described above, except for a second specificembodiment of setting down the gripping devices 3 over the spindles 8.

In this second variant of the method according to the invention, thegripper beam 2 is first positioned in such a way as to grip the emptysleeves 5, each with a sleeve gripper 4 ₁ of the gripping devices 3, andto lift them up from the pin 6 (FIG. 2a ). As can be seen in FIG. 2b ,the beam 2 is raised vertically according to the invention by a drive,which is not shown in greater detail. FIG. 2c shows that the grippingdevice 3, which is slightly inclined in FIG. 2b , is now brought intoposition over the bobbin 7 from underneath in a lateral tiltingmovement, to thereby be able to receive the full bobbin 7 in a workingposition with the unoccupied bobbin gripper 4 ₂. A correspondingarticulated connection or a corresponding pivoting joint is presentbetween the beam 2 and the gripping device 3. The movement is a pivotingof the gripping device 3, directed upward obliquely from the bottom withan offset contained therein.

The gripping device 3 is then tilted back and rotated into a retractedposition (FIG. 2d ) to then be extended again and tilted and to placethe empty sleeve 5 on the spindle 8 (FIG. 2e ). FIG. 2f then shows therenewed tilting back and FIG. 2g shows the full bobbin being depositedon the pin 6.

The method according to the invention and the doffer according to theinvention are advantageous because they are very space-saving and do notcause the machine to be wider due to the lateral extension of thedoffer. Furthermore, this is a very simple design.

LIST OF REFERENCE NUMERALS

-   1 Doffer, doffer apparatus-   2 Doffer beam-   3 Gripping device-   4 ₁ Gripping element, sleeve gripper-   4 ₂ Gripping element, bobbin gripper-   5 Sleeve-   6 Pin-   7 Full bobbin-   8 Spindle

1-15: (canceled)
 16. A method for removing full bobbins from spindles ona ring spinning machine and for setting down empty sleeves on thespindles using a doffer, wherein the doffer has a beam and a rotatablegripping device mounted on the beam, the gripping device having a sleevegripper and a bobbin gripper, and the doffer arranged next to the ringspinning machine, the method comprising the following sequential steps:(a) gripping an empty sleeve with the sleeve gripper; (b) raising of thebeam vertically; (c) extending the gripping device from the beam to aposition over a full bobbin on a spindle at the ring spinning machine;(d) removing the full bobbin from the spindle with the bobbin gripper,rotating the gripping device, and placing the empty sleeve on thespindle; (e) retracting the gripping device toward the beam; (f)lowering the beam vertically; and (g) setting down the full bobbin fromthe bobbin gripper.
 17. The method according to claim 16, wherein step(c) comprises a horizontal pivoting of the gripping device away from thebeam, and further comprising a rotational operation of the grippingdevice carried out between the steps (a)-(b) and between the steps(f)-(g).
 18. The method according to claim 16, wherein step (c)comprises a pivoting of the gripping device obliquely upward with anoffset.
 19. The method according to claim 16, wherein step (d) comprisesretraction of the gripping device toward the beam before the rotationaloperation of the gripping device, wherein the gripping device is againextended over the spindle after the rotational operation, or therotational operation of the gripping device of step (d) takes place withthe gripping device located over the spindle.
 20. The method accordingto claim 16, wherein the bobbin gripper has a bobbin receptacle that isopen at the bottom and is inverted over the bobbin for gripping thebobbin from above, and the sleeve gripper has a sleeve receptacle thatis open toward the bottom and is inverted over the sleeve for grippingthe sleeve from above.
 21. The method according to claim 16, wherein thesleeve gripper and the bobbin gripper are operated pneumatically. 22.The method according to claim 16, wherein adjacent ones of the grippingdevices on the beam are rotated with a time lag between one another. 23.The method according to claim 16, wherein the gripping device hasindicators that provide a rotational position indication of the grippingdevice through a base body of the gripping device.
 24. A doffer systemconfigured for arrangement alongside a ring spinning machine to removefull bobbins from spindles on the ring spinning machine and to set downempty sleeves on the spindles, the doffer comprising: a doffer beam; agripping device rotatably mounted on the beam; the gripping devicefurther comprising a sleeve gripper and a bobbin gripper; a driveconfigured with the doffer beam to raise and lower the doffer beam; anda drive configured with the gripping device to extend and retract thegripping device relative to the doffer beam.
 25. The doffer systemaccording to claim 24, wherein the drive configured with the grippingdevice comprises one of a joint for horizontal pivoting of the grippingdevice away from the beam, or a joint for obliquely upward pivoting ofthe gripping device with an offset.
 26. The doffer system according toclaim 24, wherein the bobbin gripper comprises a bobbin receptacle thatis open at the bottom and is inverted over the bobbin for gripping thebobbin from above, and the sleeve gripper comprises a sleeve receptaclethat is open toward the bottom and is inverted over the sleeve forgripping the sleeve from above.
 27. The doffer system according to claim26, wherein the bobbin gripper and the sleeve gripper are cylindrical orconical.
 28. The doffer system according to claim 26, wherein the bobbingripper and the sleeve gripper comprise a same diameter.
 29. The doffersystem according to claim 24, wherein an axis of the bobbin gripper andan axis of the sleeve gripper are at an angle to one another between 4°and 20°.
 30. The doffer system according to claim 24, wherein an anglebetween an axis of rotation of the gripping device and an axis of thebobbin gripper is equal to an angle between the axis of rotation of thegripping device and an axis of the sleeve gripper.